Automatic drain valve



FIG. 1 is a perspective view of an automatic drain valve in accordance with my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The portions of the automatic drain valve shown in coarse dot pattern and outlined in dashed lines form no part of the claimed design. 

CLAIM The ornamental design for an automatic drain valve, as shown and described. 